/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Reflection;
using Spring.Proxy;
using Spring.Util;

namespace Spring.Aop.Framework.DynamicProxy;

/// <summary>
/// Default implementation of the
/// <see cref="Spring.Aop.Framework.IAopProxyFactory"/> interface,
/// either creating a decorator-based dynamic proxy or
/// a composition-based dynamic proxy.
/// </summary>
/// <remarks>
/// <p>
/// Creates a decorator-base proxy if one the following is true :
/// - the "ProxyTargetType" property is set
/// - no interfaces have been specified
/// </p>
/// <p>
/// In general, specify "ProxyTargetType" to enforce a decorator-based proxy,
/// or specify one or more interfaces to use a composition-based proxy.
/// </p>
/// </remarks>
/// <author>Rod Johnson</author>
/// <author>Aleksandar Seovic (.NET)</author>
/// <author>Bruno Baia (.NET)</author>
/// <author>Erich Eichinger (.NET)</author>
/// <seealso cref="Spring.Aop.Framework.IAopProxyFactory"/>
[Serializable]
public class DefaultAopProxyFactory : AbstractAopProxyFactory
{
    /// <summary>
    /// Force transient assemblies to be resolvable by <see cref="Assembly.Load(string)"/>.
    /// </summary>
    static DefaultAopProxyFactory()
    {
        SystemUtils.RegisterLoadedAssemblyResolver();
    }

    /// <summary>
    /// Creates an actual proxy instance based on the supplied <paramref name="advisedSupport"/>
    /// </summary>
    /// <param name="advisedSupport"></param>
    /// <returns></returns>
    protected override IAopProxy DoCreateAopProxyInstance(AdvisedSupport advisedSupport)
    {
        if (advisedSupport.ProxyType == null)
        {
            IProxyTypeBuilder typeBuilder;
            if ((advisedSupport.ProxyTargetType) ||
                (advisedSupport.Interfaces.Count == 0))
            {
                typeBuilder = new DecoratorAopProxyTypeBuilder(advisedSupport);
            }
            else
            {
                typeBuilder = new CompositionAopProxyTypeBuilder(advisedSupport);
            }

            advisedSupport.ProxyType = BuildProxyType(typeBuilder);
            advisedSupport.ProxyConstructor = advisedSupport.ProxyType.GetConstructor(new Type[] { typeof(IAdvised) });
        }

        return (IAopProxy) advisedSupport.ProxyConstructor.Invoke(new object[] { advisedSupport });
    }

    /// <summary>
    /// Generates the proxy type.
    /// </summary>
    /// <param name="typeBuilder">
    /// The <see cref="Spring.Proxy.IProxyTypeBuilder"/> to use
    /// </param>
    /// <returns>The generated proxy class.</returns>
    protected virtual Type BuildProxyType(IProxyTypeBuilder typeBuilder)
    {
        return typeBuilder.BuildProxyType();
    }
}
